The present invention relates to devices for defining and measuring in space the orientation of a sighting trihedron with respect to known geographical points such as the cardinal points and the vertical, to determine angles of magnetic azimuth and elevation, thus defining a line of sight.
It is known to determine a line of sight by visual detection and oral transmission of the directions with respect to a compass, but this method is static and does not enable a target to be followed up. Radar or laser systems are also known, but they require a large and expensive infrastructure.